When rating the expected life of a rechargeable battery it is the amount of times that a battery can be discharged and charged that determines its life expectancy, this is known as the battery's service life. One discharge and charge of the battery is known as a charge cycle. It is important that when maintaining a battery that proper cycling procedure is used; this means that on the discharge portion of a cycle the battery is drained of its power to the point recommended by the manufacturer, and on the charge portion of a cycle the battery is charged and allowed to cool to the point recommended by the manufacturer. Using proper cycling procedure will maximize the life of a battery.
When maintaining a large number of batteries it becomes important to keep track of how many charge cycles have been used on the batteries. This data is used to monitor how well the batteries are being managed, what their level of usage is, and also to plan for battery replacements in the future.